public function
    Throw[T] { err Error } Observable[T]
    native('__Throw')

public operator
    catch[T] { o Observable[T], f Lambda[Error,Observable[T]] } Observable[T]
    native('__Catch')

public operator
    catch-retry[T] { o Observable[T], f Lambda[Error,Observable[Bool]] } Observable[T]
    native('__CatchRetry')

public operator
    catch-throw[T] { o Observable[T], f Lambda[Error,Error] } Observable[T]
    native('__CatchThrow')

public operator
    catch-complete[T] { o Observable[T], f Lambda[Error,Observable[None]] } Observable[T]
    native('__CatchComplete')


